Realistic lighting is an important component of high quality computer rendered graphics. By utilizing a renderer employing a global illumination model, scenes can be provided with convincing reflections and shadows, providing the requisite visual detail demanded by feature length animated films and other content. Conventionally, a ray tracing renderer may be utilized to provide global illumination in a simple manner. However, with large processing overhead and highly random data access requirements, ray tracing places a heavy processing demand for complex scenes with larger amounts of data, as with feature films and other demanding content.
Accordingly, to keep rendering times manageable and to adhere to a production schedule, a renderer needs to efficiently use available computing resources, for example by parallel processing. Conventionally, parallel rendering may be achieved by spatially dividing a single frame into multiple tiles for concurrent processing and/or by rendering multiple sequential frames, each in parallel. However, since many of the same scene objects are independently and redundantly rendered by these approaches, available hardware resources are not optimally utilized.